Thin Solid Films 397 (2001) 288–295 0040-6090/01/$ - see front matter  2001 Elsevier Science B.V. All rights reserved. PII: S0040-6090 Ž 01 . 01423-7 Influence of different physical factors on microstructure and properties of magnetron sputtered amorphous carbon films L.R. Shaginyan, A.A. Onoprienko*, V.F. Britun, V.P. Smirnov Institute for Problems of Materials Science, Ukraine National Academy of Sciences, 3 Krzhyzhanovsky str., 03142 Kiev, Ukraine Received 24 April 2001; received in revised form 27 April 2001; accepted 25 June 2001 Abstract Structure evolution of amorphous carbon (a-C) films deposited by dc magnetron sputtering of graphite in argon was investigated as a function of substrate temperature T (20–8008C) and dc substrate bias voltage U (floating — y175 V). Film structure was s b studied by transmission electron microscopy, selected area electron diffraction, reflective high energy electron diffraction and Raman spectroscopy. Film resistivity in two directions — parallel and perpendicular to the substrate — was also measured. The results obtained allow for the assumption that the film structure is based on coexistence of D- and G-phases formed of sp bonded 2 carbon atoms. G-phase consists of small graphite-like ordered areas embedded in continuous uniform amorphous D-phase. The evolution of a-C film structure in 20y4508C interval occurs by temperature induced graphite-like ordering of small areas within D-phase (G-phase nucleation). In the 500–8008C range the change of C-film growth mechanism takes place. Instead of nucleation of the G-phase within the D-phase the initial nuclei of graphite phase appears on the substrate. The changes of a-C film microstructure under the ion bombardment in the range of y20FU Fy150 V are accompanied by decreasing of G-phase b clusters size and simultaneous certain disordering in their internal structure. At U )y150 V the cluster structure tends to be b more ordered towards it graphitization. The effect of graphite-like clusters ‘texturing’ revealed in a-C films under the ion bombardment is discussed.  2001 Elsevier Science B.V. All rights reserved. Keywords: Amorphous materials; Carbon; Ion bombardment; Structural properties 1. Introduction Although a lot of papers have been devoted to the investigation of a-C films structure the question about film short-range order is still open for discussion. One of the most important reasons for this seems to be the ‘polymorphism’ in amorphous carbon. Actually, it is known that different types of atomic bonding are formed in a-C films depending on the deposition method and deposition parameters that result in different film prop- erties w1–5x. Thus, when studying the structure of a-C condensates it is expedient to consider its evolution in films deposited by the same method but under variation * Corresponding author. Tel.: q380-44-4443401; fax: q380-44- 4442131. E-mail address: onopr@materials.kiev.ua (A.A. Onoprienko). of some of the deposition parameters which essentially influence the film microstructure. In particular, it is known that the film structure strongly depends on such physical factors as the bombardment of growing film with energetic particles (ions) and substrate temperature (T ). Therefore, these factors could be successfully used s as a powerful instruments for studying the structure and properties of a-C films. The influence of the ion bombardment (IB) on the atomic bonding in DLC films is a well established fact. For example, the sp y sp ratio strongly depends on the 2 3 energy of the ions bombarding the growing DLC film w6,7x. At the same time the influence of the IB on the structure of carbon films deposited by magnetron sput- tering of graphite target in argon was barely investigated w8x. However, Neuville and Matthews w9x mention that if a conventional sputtering is used (with a high pro-